


Inevitability

by Avengers_Whore



Series: Marriage is Better the Second Time [2]
Category: Marvel Cinematic Universe
Genre: Alpha/Alpha/Omega, Alpha/Beta/Omega Dynamics, Angst with a Happy Ending, Avenger Loki (Marvel), Avengers: Endgame (Movie), Avengers: Endgame (Movie) Spoilers, Fix-It, Fluff, Fluff and Angst, M/M, Multi, Parent Loki (Marvel), Parent Stephen Strange, Parent Tony Stark, So much fixing, The ending Tony actually deserved tbh, Tony Stark Feels, Tony Stark Has A Heart
Language: English
Status: Completed
Published: 2019-05-05
Updated: 2019-05-05
Packaged: 2020-02-25 23:38:24
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 4,620
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18712012
Author URL: https://archiveofourown.org/users/Avengers_Whore/pseuds/Avengers_Whore
Summary: ENDGAME SPOILERS. DO NOT READ IF YOU HAVEN'T SEEN THE MOVIE.-Everything had gone to shit. Like usual. But...they were all there. Working together like they were all supposed to. Saving the universe from this mad Titan’s terror. And damn him if he wasn’t going to see it through.This is a sequel to Custody. I recommend reading that one first if you haven't already.





	1. The Endgame.

**Author's Note:**

> I can't believe I wrote this in a handful of hours. It's definitely not long but I'm planning a second chapter to give us a lot more FrostIronStrange fluff with their puppies! So stay tuned for that.
> 
> Also yeah I'm still feeling all of the feels after Endgame and tbh Marvel, specifically the Russo bros, will never be forgiven for what they did to Tones and Nat.  
> (But they're not on my bad side bc Peggy deserved to have her true love and that was Steve who also deserved his true love!)

A soft lullaby played over the speakers in the nursery, matching with Tony’s humming as he slowly walked around the room. He held a newborn pup in his arms, barely two weeks old and still having he and his mates wrapped around her itty, bitty finger. The baby girl was quietly watching her mother’s face with big, newborn-blue eyes. Time would tell if they would stay blue like Stephen’s or turn green like Loki’s. The omega secretly hoped they wouldn’t turn brown.  
The little girl shifted slightly in his arms and stretched out her arms and legs, making a soft snuffling sound before she settled into a comfortable decision once more. Tony purred softly and nosed along the side of her face, breathing in her baby smell.  
“I promise you will never know a thing of hardship,” he murmured against her soft cheek. “You will always be loved and always protected. Your daddies will spoil you rotten, little princess, and your brothers will always be around to take care of you, Morgan Stark.”  
“You’re adorable,” Loki murmured as he came up behind the omega, wrapping his arms around the smaller man and resting his chin on his shoulder. He rumbled happily at the sight of the baby girl.  
“I think you’re both adorable,” Stephen commented, pressing a kiss to the side of Loki’s head before coming around to stand in front of both of them. He smiled warmly at Morgan and cast a few harmless sparks above her head, making the girl giggle and reach up with her little hands.  
Loki gently took the babe from his mate’s arms and scented her as he rocked her back and forth. She yawned and stretched herself out once more before she closed her eyes, one of her hands loosely curling around a lock of her daddy’s hair. He walked over to her bassinet and set her inside, laying a soft blanket over top of her.  
“Good night, darling,” he murmured before he pulled away. Stephen went over and pressed a kiss to the little pup’s forehead before both alphas stepped away. Tony caressed a thumb over her cheek before he pulled away as well, walking out of the nursery with his mates.  
-  
“Ste-Stephen,” Tony panted softly, one hand pressed to the bleeding wound in his side as he stumbled closer to his mate. Thanos had been gone for what seemed like days now. It was just them and the Guardians left on Titan and now everyone was oddly quiet.  
“I’m sorry, Tony. It was the only way,” Stephen murmured softly, looking his omega with solemn eyes. He’d given up the Time Stone to save him, had said they only won in _one_ future. The beginnings of a portal opened under his feet.  
“Stephen what are you doing? Alpha-”  
“Go take care of our pups.” And that’s when the others started...dusting, if he had to pick a word. Fading away. Tony’s eyes widened and he looked at Stephen with teary eyes. Their eyes met once more before he was forced through the portal and found himself on the ground in Wakanda. He tried to blink away the tears but they kept coming, sobs wracking his body.  
“Anthony,” a voice called before a body slid to his knees beside the omega. Arms wrapped around him and the familiar scent of Loki filled his nostrils. He immediately latched onto his other mate and cried into his chest.  
“Loki, Loki, I lost him, we lost him,” the omega wailed, one of his bondmarks beginning to sting. He was sure the god could feel the stinging from his own bondmark. The arms around him tightened slightly and they curled around each other.  
“Boss,” FRIDAY murmured in his ear. “Peter didn’t make it either.”  
And wasn’t that the cherry on top?  
His 7-year-old was gone. Ripped away from him just like one of his mates. He barely even noticed as he was lifted and carried away from the battlefield, shock settling in and leaving him shaky and nearly catatonic. He could just make out Loki’s voice in his ear but he had no idea what he was saying.  
He must have passed out because when he woke up, he was in medical hooked up to a few machines. He looked around and found Harley and Morgan curled up on a couch. He could make out a faint shimmer of Loki’s magic keeping the two from rolling off.  
“It’s not just about you!” That was Loki. He sound angry.  
“Brother-” Thor.  
“We all fucked it up, brother, we are all to blame,” Loki hissed. Tony sat up and winced at the pain in his side. Right, Thanos had stabbed him. He pushed through the pain and detached the wires and the IV, getting up and heading over to the door.  
“Everyone needs to calm down,” Steve ordered, making Tony freeze in his tracks. He took a deep breath before he opened the door and stepped out, closing the door behind him. It had been over a year since Steve came back and he still didn’t want him anywhere near Harley or Morgan.  
“Calm really isn’t on anyone’s agenda,” he said, holding a hand to his side as he came over.  
“Tony,” Steve said with a sigh. “We’re really going to need your help on this one.”  
“Oh now you want my help? Now, after I warned all of you this was coming?” Tony snapped, baring his teeth in a snarl. “I was the first one to say it! All the way back when Bruce and I built Ultron! Well, I’m done. Do it yourselves, I have two pups to care for.”  
“Two?”  
“Peter’s gone,” he hissed. His knees buckled from all of the sudden energy and he grunted, leaning into Loki as he wrapped an arm around him.  
“Back to bed, love, you need to rest,” the trickster murmured into his ear, picking the omega up. He took him back into the medical room and laid him on the bed. He walked over to the pups and picked them up, laying them with their mother.  
“Mommy,” Harley murmured, shifting slightly and laying his head on Tony’s chest. He breathed in his familiar scent and allowed it to settle him back into sleep. Morgan remained asleep against his side. Loki ran a hand through Tony’s hair, soothing the omega’s frayed nerves. He looked over his mate and pups with a small frown on his face.  
“The house in the woods,” the alpha muttered, drawing Tony’s attention. “That is a good spot, right? To raise them.”  
“Yeah,” the genius replied with a nod of his head. “It’s perfect.”  
-  
Everything had gone to shit. Like usual. But...they were all there. Working together like they were all supposed to. Saving the universe from this mad Titan’s terror. And damn him if he wasn’t going to see it through. He watched Carol get thrown and knew that was his moment. He launched himself and grabbed onto the gauntlet, snatching the stones from the gauntlet before he was tossed aside like a ragdoll.  
“I am inevitable,” Thanos repeated, loudly, everyone’s hearts beating just as loud as the world seemed to freeze. He snapped.  
Nothing.  
Tony sat up on his knees, his right hand raised as the nanotech morphed around the stones in his palm, placing them where they needed to be. The pain - that was excruciating. But he’d had open heart surgery without painkillers in a cave, he’d suffered palladium poisoning, flown a nuke into space.  
He’d been beaten, broken, bruised, he’d given birth for fuck’s sake, he’d fought two super soldiers in a bunker, and he’d been stabbed with his own tech. He didn’t even scream as he felt the stones and their power, merely taking it in stride and baring his teeth in a snarl at the Titan.  
“And I...am…”  
“Anthony, _no!_ ”  
“Iron Man.” Snap. White light. He stumbled forward and fell back against a piece of rubble, heart beating fast, blood rushing the only sound he could make out in his ears. His vocal chords felt tight and unresponsive no matter how much he tried to speak.  
Steve was the first face that came into view, the blond alpha’s mouth moving but he couldn’t make out the words. Hands pushed him aside and green eyes filled his vision as the frantic god cupped his cheeks and held eye contact with him. Stephen was beside him in the next second, icy blue eyes wide and frightened.  
Green and orange light started in his vision and slowly but surely, the frantic voices all around him finally came into existence. He took a shuddering breath and all of the muscles in his body relaxed all at once. His eyes flickered back and forth over his mates’ faces before moving passed them to look at all of the others.  
“Lokes,” he rasped, his throat feeling burnt out and dry.  
“There you are, love, just keep focusing on me,” Loki murmured, his attention focused on the green wisps dancing around his fingers. Stephen was just as focused, both shaky hands hovering over the right side of the omega’s body.  
“FRIDAY,” Stephen said urgently.  
“Boss’s vitals are coming back into balance,” the AI replied, the relief in her voice unmistakable. “Boss, Peter is on the line. Shall I put him through?”  
“Y-Yeah,” he managed. A click sounded.  
“Mama!” Peter gasped into his ear, making the omega smile tiredly as he heard his pup’s voice. No longer the oldest since Harley was now 10 but they’d work through that no problem. So long as he got to hug and kiss his baby again.  
“Petey. You okay?”  
“Yeah, I’m fine. Are you? You don’t sound good? Is daddy there? Papa?” The boy’s voice was a mile a minute, making his parents smile wide.  
“We’re right here, Peter. Do us a favor and call Happy to come get you,” Stephen told the pup. “And then we’ll come get you.”  
“Okay,” the pup answered before he hung up.  
“You’re never allowed to do anything like this ever again,” Loki murmured as he and the other sorcerer finished their healing.  
“Got it,” Tony answered with his usual winning smile. Stephen laughed and ran a hand through his hair, leaning heavily against Loki’s side and breathing in the other alpha’s scent.  
-  
“Mom!”  
“Mama!”  
“Mommy!”  
Tony let out an oomph as his three children tackled him to the ground, piling on top of him and wrapping their arms around him. He laughed and hugged them back, tightening his hold and pressing kisses to the top of their heads. Harley was holding on especially tight, his eyes wide as he looked at the faded burns across the right side of his face. They would fade with time.  
Peter was babbling on and on about how he must’ve passed out and how he’d had no idea where they’d all went and why did he have burns on his side and why were his daddies bleeding. Tony sat up with all of his children and just continued to hold and scent them.  
A little hand reached up and touched the marks on his face, drawing his attention down to 6-year-old Morgan, his other little alpha baby. The little girl looked thoughtful, entirely too bright for being so young just like the rest of them. She leaned up and pressed a kiss to her mother’s cheek.  
“Thanks, Squirt,” he murmured with a smile, nuzzling her cheek.  
“Everything’s all right,” Loki told them as he knelt next to them, pulling Peter into his arms and kissing his forehead. Harley launched himself at Stephen, wrapping his arms around the alpha’s neck and refusing to let go for the world.  
“We’re all together again,” the sorcerer told the omega boy, kissing the side of his head and picking him up off of the ground despite the fact he was far too big now.  
“I missed you, papa,” Harley whispered tearfully. Tony stood up with Morgan in his arms and he smiled warmly at the sight. Even when the 10-year-old tried to act tough, tried to act like he could handle everything anyone threw at him, he still needed the comfort of his parents.  
“Alright, I think we all just need a day in the nest,” Tony announced, poking Morgan’s side and smiling at the giggle he received. His mates followed him inside of their house and they all went upstairs to the master bedroom. Even when Stephen and Peter had been gone, they’d made sure the nest was still big enough for all six of them.  
They all crawled inside the nest, laying back against the fluffy pillows and soft blankets. They were all on top of each other and curling close, breathing in familiar scents and re-establishing faded ones. Everything was...how it should be. Perfect. All he ever wanted.


	2. Just Right

**Summary for the Chapter:**

> Just a glimpse into raising Harley, Peter, and Morgan, along with another little surprise near the end!

“Morgan Stark, what have I said about the garage?”  
“That I can’t be in it without mommy or daddy supervision.”  
“So then why are you in the garage?”  
“Because I wanna be.”  
Loki snorted in his attempt to keep from full out laughing. His mate was standing in front of their daughter with his hands on his hips and looking somewhere between fondly exasperated and irritated. The omega whipped his head around to glare at the alpha before turning back to the 6-year-old alpha girl.  
“Morgan.”  
“Mommy,” the pup replied, putting her hands on her hips to mirror the older brunet.  
“Honey, if you want to work in the garage with mommy, all you have to do is ask!”  
Morgan faltered slightly and dropped her hands from her hips, her brow furrowing and a little frown appearing on her cute face. Big green eyes looked up into honey brown.  
“Really?”  
“Really, baby,” Tony murmured, bending down and picking her up. “But for now, it is definitely bath time. Loki, go get Peter please.”  
“Of course, love,” the alpha replied, pressing a kiss to his cheek and nuzzling Morgan before going to fetch their eldest-turned-middle child. Peter was sitting at the table with a book on biology in front of him, quietly reading while Stephen fiddled around washing the dishes. “Peter, bath time.”  
“When did Harley stop taking group baths?”  
Stephen paused and Loki blinked at the question, crossing his arms over his chest and leaning against the archway. He was silent for a moment as he thought, meeting the other sorcerer’s eyes across the kitchen.  
“A couple years ago, I suppose. He was seven or eight, I believe,” the god replied slowly, frowning slightly when Peter didn’t look up from his book.  
“I’m twel- I mean...seven. Why can’t I take baths by myself?” Peter asked now, flipping a page in his book.  
“If you really want to, Pete, you can. I just thought...you’ve always loved bath time with me and mum,” the older alpha told him, walking over and sitting next to the pup. He didn’t miss the boy’s slip about his age. The smaller alpha merely nodded his head and continued to read his book. Loki glanced up at Stephen before heading up to the bathroom to join Tony and Morgan.  
Stephen finished drying the dishes before walking over to Peter and quietly closing the boy’s book, pushing it forward a little to get it out of the way. He sat down next to the boy and turned the chair so the brunet faced him.  
“Talk it out with me, Petey,” the doctor said, gently tilting the boy’s face up. Big, honey eyes looked up at him and the alpha smiled slightly, loving how much he looked like his mother.  
“Everything’s different now. I was the oldest, I was the big brother who needed to take care of his little brother and sister,” Peter told him with a sigh. “But now Harley’s the older one. And I don’t know what to do.”  
“I think I know how you feel,” the sorcerer told him quietly. “It sounds like you and I are just feeling...a little out of time. It was 2018 one minute and the next it was 2023. And the world, they all aged without us. But that doesn’t make this family any different Peter. You were going to be our little boy even if you were 21.”  
Peter smiled slightly and gave a soft laugh, looking away from his papa. Stephen smiled and picked the boy up as he stood, rubbing his back and nosing along his cheek affectionately.  
“If you’re dead set on it, you can bathe by yourself from now on just like Harley,” he told the boy. “But don’t think you have to give it up just because you’re supposed to be the oldest.”  
“...Can we go up to the tub?”  
“Of course, Petey.” Stephen kissed his cheek and carried him up the stairs to the master bedroom and into the attached bathroom. Loki and Tony were already in the large tub with Morgan between them, the small alpha splashing around and playing with them. Harley was kneeling by the edge of the tub with a smile on his face.  
“There’s my other baby,” Tony purred, making grabby hands for Peter. Stephen set him down and helped him out of his clothes before the brunet climbed into the bathtub with them. The genius wrapped his arms around the alpha boy and dumped water all over his head with a chuckle.  
-  
Tony laid back in the nest waiting for his mates to finish their nightly routines and come join him. He was only wearing one of Stephen’s shirts and lace pair of red panties, his legs spread open to show off the color against his tanned skin. He heard footsteps and purred, smirking when both alphas walked into the bedroom.  
“Now what is this?” Loki rumbled, his scent spiking as he eyed the tempting omega in the nest. He was still shirtless after their earlier bath, only a pair of black sweatpants to be seen on his pale body. He walked over to the bed with Stephen on his heels, crawling over the omega.  
“Looks like dessert to me,” Stephen replied, getting in next to them and running his scarred hands over their mate. He watched as Loki got down between their mate’s legs and bit possessively at his bare thighs.  
“Tastes like dessert too,” the god murmured, licking over the teeth marks he’d left behind. “Tell us what you want, pretty omega.”  
“Want you to fuck me,” Tony purred, spreading his legs even wider and arching his back temptingly.  
“Yes, that’s obvious, you tempting thing,” Loki rumbled with a grin.  
“But you only wear _these_ for special occasions,” Stephen said, caressing a finger along the bright lace.  
“Maybe I want you to put another pup inside me,” the genius teased with a smirk on his face. “Hmm? Fill me up and get me pregnant again, alphas?”  
“ _Fuck_ ,” Stephen swore, groaning softly before he started yanking the shirt off of the omega. Loki still seemed to be short-circuiting, his eyes wide as he looked at Tony. The brunet got up and pushed Stephen onto the bed, crawling on top of him and kissing him senseless.  
Nimble fingers trail over his hips and pull the panties down slowly, teasing the omega as Loki squeezes his perky ass. Tony whines softly against Stephen’s mouth and pulls back to pant as he feels a thumb on his hole.  
“You’re a tease, my darling,” the god murmured against the small of his back, placing kisses and nips along the skin there.  
“More than a tease,” the other sorcerer growled, lunging at his mate’s neck and fitting his teeth over one of the bondmarks. The omega cried out and arched his back, slick pouring out of him much to Loki’s amusement. The god pushed a finger inside which only intensified the brunet’s pleasure.  
“Mama!”  
Tony snapped up and was immediately off of the bed, pulling on sweatpants and a robe before hurrying down the hall towards Peter’s room. Loki and Stephen blinked, surprised for a moment. Both took a moment to compose themselves before following after their mate.  
Peter was clinging to his mother with tears in his eyes, the young boy trembling minutely as Tony held him and rubbed his back. Harley was on the other side of the room in his own bed, watching them both with concerned eyes. Stephen walked over to Tony and Peter while Loki went to Harley, running his hands through the boy’s blond curls.  
“What’s wrong, Petey?”  
“I-I saw- I don’t know,” the alpha whimpered against Tony’s chest. “There were people I didn’t know and the sky was- it was orange? But I didn’t know anyone and everyone was so sad.”  
“It’s okay, baby,” Tony murmured, kissing the top of his head. “You’re not there anymore. You’ll never be there again.”  
“What was it?”  
“That was the inside of the Soul Stone,” Stephen told his son quietly, placing a hand on his back. “I saw it too. I know how scary it must’ve been for you.”  
“Do you wanna sleep with us tonight? Or do you wanna stay with Harley?” Tony asked quietly.  
“You can sleep in my bed, Petey,” Harley told him as he came over, Loki by his side. The omega took his brother’s hand and squeezed lightly, smiling at the older-turned-younger. The young alpha smiled slightly and nodded his head, crawling out of his mother’s arms and into Harley’s.  
“You’re a good brother,” Loki told the blond boy, kissing the top of his head. He pressed a kiss to the side of Peter’s head, rumbling happily in his ear before he pulled back. Harley purred and lead Peter over to his bed, helping him in and then crawling in after him. Tony tucked them both in and kissed their cheeks before he stood up.  
“Goodnight, boys,” he purred, his smile bright and happy as he looked at his two boys. The three adults turned off the lights and left the room, checking in on Morgan before returning to their room.  
-4 years later-  
Tony frowned slightly as he felt Harley’s forehead, feeling the heat coming from his flushed face. He looked the 14-year-old over and looked at the teen’s pupils with a twist in his mouth as he nodded his head.  
“Yeah, sounds like you’re starting your first heat,” he told the boy softly. The teenager had woken up feeling sluggish and overheated that morning but had felt fine enough to go to school. He’d come home early complaining of severe cramps and the nurse had said he had a fever.  
“Don’t wanna,” the blond grouched, a scowl on his face. Tony smiled slightly and ruffled his curls.  
“I didn’t either, kiddo, but it happens to the best of us. Why don’t you go take a shower while I get everything ready?”  
“Okay,” Harley mumbled before dragging himself up the stairs to the bathroom. Tony watched him go and ran a hand through his hair.  
“At least he’s the only omega so far. If you’re lucky, Stephen and I will be the only ones left to deal with the sex and rut talks,” Loki teased as he wrapped his arms around the brunet.  
“Unless Nat ends up an omega,” he replied with a chuckle, leaning back in the god’s embrace. Two years ago, they’d had their last pup, another darling little girl. Tony had been insistent on naming her Natasha and wouldn’t budge for the world. She looked nothing like his redheaded friend, the woman he’d considered a sister, but he hoped and prayed she’d be just as tough and just as loving.  
“For all our sanity, I hope she’s a beta,” Stephen told them as he walked by, holding an old tome in one of his hands. His mates chuckled for a moment before Tony pulled away to gather the snacks and water Harley would need.  
“I will grab a blanket from our nest. It should soothe him at least a little,” Loki called before he headed up the stairs to do just as he said. Tony followed him up after a moment, going into Harley’s room and setting everything on the side table. Peter would need to share a room with the girls for the week but the 11-year-old didn’t seem to mind too much.  
Harley came into the room in a t-shirt and sweatpants, his hair still a little damp and his cheeks still flushed a light pink. He walked over to Tony and wrapped his arms, burying his face in his chest with a soft whine.  
“I know, baby, I know,” the older omega soothed, rubbing his back and guiding him over to the bed. “Let’s start a nest, huh? That’ll settle you a bit. Look, your daddy brought some of the blankets from our nest to build with.”  
“Okay,” Harley murmured, his usual bravado dimming down from the heat. He picked up some of the blankets and started arranging them on his bed, biting his lip as he looked it over. Tony watched him with a small smile on his face, seeing the builder gleam in his son’s eyes that he knew came from him.  
“Beautiful, baby,” he murmured as the younger omega finished and crawled inside, squirming and rolling around to cover the blankets and pillows in his scent. Tony moved all of the snacks and the water bottles closer to the nest and reached in to caress the teen’s cheek.  
“It hurts,” Harley whimpered quietly.  
“I know baby. Just gotta ride this heat out and then we can get you suppressants, okay?”  
“Okay,” he murmured, curling up on his side and whining. “I want papa.”  
“Then I’ll go get him. Drink some water okay?” Tony told him before he left the room to go find Stephen. The alpha was sitting at the kitchen table with the tome, sipping on a cup of tea. The omega wrapped his arms around him and pressed a kiss to his neck.  
“Well hello there,” the sorcerer murmured, a small smile on his face as he broke his focus from reading. “What can I do for you?”  
“Not for me,” he told him with a smile. “Harley wants you to go up.”  
“Guess I better head up then,” Stephen said, kissing his mate’s cheek.  
-  
“Not that it’s a competition, but Morgan said she loved me _3000_. You two were in the low 600-900 range,” Tony teased as he came down the stairs. He plopped down on the couch between his mates and purred as they filled in on his sides.  
“Oh however will we survive?” Loki drawled sarcastically, a smirk playing on his lips as he nosed over the omega’s bondmark.  
“I guess we’ll have to settle for second best,” Stephen continued, growling jokingly as he nipped at Tony’s ear.  
“Damn right you will,” the omega said with a grin. They all turned their heads when they heard little thumps on the steps and smiled when Natasha poked her head around the corner. The small brunette looked cute in her Black Widow onesie, tired blue eyes looking at them as she toddled over.  
“And just how did you get out of your crib, lil lady?” Tony murmured as he picked her up and settled her on his lap. The 2-year-old leaned back against his chest and grabbed Loki’s hand, fiddling with it.  
“I climbed,” she stated bluntly, looking up at her parents.  
“Why am I not surprised,” Stephen murmured with a smile on his face. He leaned down and pressed a kiss to the top of the toddler’s head. The pup squeaked and smiled up at her papa. Tony sighed happily and leaned his head on Loki’s shoulder, purring contently.  
Now _this_ was perfect.


End file.
